CME configured as SRST fallback in MGCP mode

Cisco CME can be configured in SRST mode and is better option than normal SRST.CME in SRST support more feature compare to normal SRST and support less phone compared to CME as SRST

The configuration is pretty simple ..

For MGCP fallback you need to configure

ccm-manager fallback-mgcp

Then configure the below command to fallback to H323 in case of failover:

global
  service alternate DEFAULT

Then configure the SRST fallback in CME

telephony-service
srst mode auto-provision none

 srst ephone template 3  // Define the default template to be used for phone if the phone is not previously added in the configuration

srst dn template 2  // Define the dn template to be used for the phone if the phone is not previously added in the configuration

Define the dn line mode

srst dn line-mode dual

max-ephones 58
 max-dn 100
 ip source-address <CME port ip > port 2000 // Ip will be the one that phone will communicate for sccp


Verification command:

show telephony-service
show ccm-manager fallback-mgcp
debug ephone details
show telephony-service
show telephony-service ephone
ip tcp adjust-mss
session transport tcp